In a manufacturing process of a semiconductor integrated circuit, a coating and developing processing employing a photolithography technique has been performed to form a resist pattern on the surface of a semiconductor wafer or an LCD substrate (hereinafter, referred to as a “wafer”). The coating and developing processing employing the photolithography technique includes a resist coating process of applying a resist liquid onto the surface of the wafer, an exposure process of exposing a circuit pattern to be transferred on the formed resist film, and a developing process of supplying a developing liquid to the wafer after the exposing process.
Further, various types of thermal processing are performed in the coating and developing processing employing a photolithography technique.
For example, a thermal processing (a pre-baking process) that evaporates residual solvent in the resist film to improve adhesion of the wafer and the resist film is performed between the resist coating process and the exposing process. Further, a thermal processing (a baking after exposure process (PEB; Post Exposure Bake)) that induces an acid catalized reaction in chemically amplified resist (CAR) is performed between the exposing process and the developing process. Still further, a thermal processing (a post-baking process) is performed after the developing process to remove the residual solvent in the resist film or a rinse liquid flowed into the resist during the developing processing for preventing the infiltration of the residual solvent and rinse liquid during wet etching.
The condition of the respective thermal processing described above may be strictly regulated to manage the Critical Dimension CD of the resist pattern to be formed. In particular, in a case where the chemically amplified resist (CAR) that has received a wide attention recently due to its capability of accomplishing a high sensitivity, a high resolution and a high resistance over the dry etching is used as a resist, the condition of the thermal processing of the bake after exposure process may be strictly regulated because the difference in the amount of heat being supplied to the resist film at the respective sites within a surface of the substrate has a severe effect on dimension precision of the circuit pattern in the integrated circuits of semiconductor devices to be manufactured.
Japanese Patent Laid-Open Publication No. 2003-51439 discloses a thermal processing method and a thermal processing apparatus in which, in order to manage the condition of the thermal processing, the output amount of heat source is controlled to make the amount of heat being supplied to the substrate during the thermal processing to be the same at a plurality of sites on the substrate.